(1) Field of the Invention
This invention relates to a pre-wired terminal connecting block which provides an interface between large numbers of electrically conductive wires in a telecommunication system and, more particularly, to an interface which utilizes a printed circuit board.
(2) Background Art
Under regulations of the United States Federal Communications Commission ("FCC"), each type of telephone circuit must be terminated in a specific interface jack and receptacle. The interface jacks and receptacles are referred to by a particular designation under the Universal Service Order Code ("USOC").
Residential service is provided with the common, modular jacks which have become the standard for connecting all FCC registered telephone equipment. Residences will rarely have more than two telephone lines or circuits. Small businesses may use multiple lines of various types, thereby requiring many separate, small interface jacks or receptacles. Large businesses may additionally require multiple circuit interfaces connected to large capacity interface jacks. Fifty-pin (twenty-five pair) jacks may be used and carry from six to twenty-five circuits each, depending on the number of leads utilized for each circuit. In general, such interfaces require that a multiplicity of incoming telephone lines be routed either to the telephones themselves or to another interface as dictated by the user's particular telephone system arrangement.
A commonly used terminal connecting block is referred to as the "66-type" quick connect block. Such a connecting block includes an upper portion, having a multiplicity of connecting clips, which is supported by a standoff mounting bracket or the like. The various incoming wires may be connected directly to the connecting clips on site in a desired arrangement. In addition, each connecting clip may have a post extending through a rear surface of the block and wires are wire-wrapped to each post in the factory in a desired arrangement. The wires may also extend to standard receptacles carried by the supporting bracket. In this manner, the block may be pre-wired and merely installed on site. Examples of known terminal connecting blocks are shown in U.S. Pat. Nos. Re. 31,714 and 3,836,942.
Such prior art connecting blocks have a number of disadvantages. Manufacture and installation of the blocks are quite labor intensive and time consuming, requiring that a large number of wires (upwards of one-hundred wires or more for each block) be either hand wired to the connecting clips on the block or individually wire-wrapped to the posts beneath the block. In repeatedly connecting such a large number of wires, it is likely that one or more wires will be connected to the wrong location on the terminal block. All of the incoming and outgoing wires are exposed and interwoven, often creating a confusing "rat's nest" of wires. Such exposed wires can easily become unkempt, or disconnected or severed, causing significant maintenance problems. Moreover, since the wires are exposed, it is easy for the interconnections to be tampered with by the customer, an eavesdropper or other unauthorized persons.